Reproductive Response of Adult Siberian Hamsters to One-Hour Melatonin Infusions

Authors : Bülent GÜNDÜZ

Pages : 57-63

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Publication Date : 2003-12-01

Article Type : Research Paper

Abstract :The pineal hormone melatonin is known to play an important role in mediating photoperiodic messages to the reproductive system in seasonal breeding animals. In this study, we investigated whether a 1 h subcutaneous infusion of 50 ng of melatonin at 2000-2100 hours, effective in causing inhibition of testicular development in the juvenile Siberian hamsters insert ignore into journalissuearticles values(Phodopus sungorus);, would cause testicular regression in adults of this species housed on a long photoperiod insert ignore into journalissuearticles values(LD16:8);. Pinealectomized adult hamsters received programmed subcutaneous infusions of 50 or 500 ng of melatonin or vehicle insert ignore into journalissuearticles values(0.12 ml); at 2000-2100 hours each day for 8 weeks. We found that the testicular weights of infused animals receiving melatonin or vehicle were not different from each other; all animals retained large testes. These results show that a 50 ng melatonin infusion at a particular time point insert ignore into journalissuearticles values(2000-2100 hours); is not effective in altering the functional status insert ignore into journalissuearticles values(size); of the testes of adults.
Keywords : Melatonin, Siberian hamster, Photoperiod, Testes, Infusion